This invention relates generally to signalling devices for use on emergency vehicles, for example, and more particularly to a signal light of the type incorporating an oscillating lamp.
In signal lights of this type, the lamp is typically mounted for oscillation about two generally perpendicular axes (e.g., horizontal and vertical axes) for generating a beam of light repetitively movable through an unchanging predetermined path of travel, such as a Figure--8 pattern. However, conventional lights designed to trace beam pattern of this type are largely ineffective inasmuch as the beam fails to sweep all areas within the outer perimeter of the pattern, resulting in substantial gaps or blind spots in the pattern. Reference may be made to U.S. Pat. Nos. 2,221,483, 2,409,046, 2,417,934, 2,510,892, 2,677,121, 3,546,669 and 3,821,541 for signal devices generally in the field of this invention.